The present invention relates to improvements in a temperature compensation circuit for strain gauges used in load cells, etc.
More particularly, the invention relates to a novel strain gauge temperature compensation circuit adapted to compensate for variations in strain gauge output due to temperature variations with high accuracy.
It is well-known that load cells are widely used as weight detectors for weighing machines. A beam is fixed at one end thereof and an object to be measured is placed at the other end, so that weighing is effected by taking out a change in resistance value, as an electric signal, corresponding to the amount of strain in the strain gauge fixed to a portion of the beam. Because of the use of a nickel resistor alone as a compensation resistor in the temperature compensation circuit of such conventional strain gauge, the ability to compensate for variations in strain gauge output due to variations in the temperature of objects to be measured has been insufficient and it has been difficult to maintain satisfactory accuracy of measurement in practice. The present invention is intended to provide a temperature compensation circuit for strain gauges which eliminates the longstanding problem with the conventional strain gauge temperature compensation circuit and which is high in temperature compensation accuracy and in yield of production.